1. Field of the Invention
This invention relates generally to composite video signal generating devices and, more particularly, but not by way of limitation, to a monolithic video display processor which can superimpose one or more mobile patterns at selected locations on a larger, fixed pattern image.
2. Prior Art Statement.
Although numerous systems have been proposed for digitally generating composite video signals containing desired display patterns, such systems have been generally confined to relatively fixed pattern images. Examples of such systems are shown in U.S. Pat. Nos. 4,107,664 and 4,129,858. In contrast, some systems have been proposed to provide relatively fixed pattern images, but with one or more mobile patterns which may be displayed at selected displacements relative to the fixed pattern image. In the latter type systems, however, the display capabilities are generally constrained by the limited size of a dedicated memory area, as in U.S. Pat. No. 4,119,955, or by the limited time period reserved for processing the mobile patterns, as in U.S. Pat. No. 4,116,444. Other systems of general interest are shown in U.S. Pat. Nos. 3,345,458; 3,891,791; 3,918,039; 4,034,990; 4,081,797; and 4,107,665.